code refactoring, loading env variable, adding support for headless Firefox, upload file to shared folder

Describe the general shape of this PR (new feature? refactor? bug fix? one-line change?) code refactoring, loading env variable, and adding support for headless Firefox
Describe what changes are being made
env variables are loaded at start
Firefox browser is launched with headless option
Code is refactored
File is uploaded to the shared Google Drive. Note - You must no longer be logged in as the 'Agenda Scraper' google account. You must be logged into your own google account that has the 'Cities' folder shared with you with Edit permissions
A city folder will be created under the shared 'Cities' folder if the fodler does not exist
The city name under the shared 'Cities' folder is the same as the city name used when the program is invoked. So if the program is invoked as Legistar_Selenium.py sunnyvaleca "Last Year" "Sustainability Commission" the folder sunnyvaleca is created (if it does not exist) under the shared 'Cities' folder and the .csv files uploaded there.

[ ] Linked to the Github Issues being addressed using the right sidebar :arrow_right:
[x] Have you discussed these changes with the project leader(s)?
[ ] Do all variable and function names communicate what they do?
[ ] Were all the changes commented and / or documented?
[ ] Is the PR the right size? (If the PR is too large to review, it might be good to break it up into multiple PRs.)
[ ] Does all work in progress, temporary, or debugger code have a TODO comment with links to Github issues?
[ ] If you changed the user interface, did you add before and after screenshots to below?

codeforsanjose / city-agenda-scraper